Volume 17, Issue 9 (2017)                   Modares Mechanical Engineering 2017, 17(9): 327-338 | Back to browse issues page

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Movahedi A, Dehghan A A, Dehghan manshadi M. Experimental Investigation of aero acoustic noise generation process from a wall mounted square cylinder at incidence. Modares Mechanical Engineering. 2017; 17 (9) :327-338
URL: http://journals.modares.ac.ir/article-15-3609-en.html
1- Yazd University
2- Malek Ashtar University of Technology
Abstract:   (1472 Views)
In the present research aeroacoustic characteristics of flow over a finite height wall mounted square cylinder at different angles of attack is investigated. The aspect ratio of the model and the boundary layer thickness were 7 and δ⁄D=4.27, respectively. The experiments were done in a acoustically improved aerodynamic wind tunnel. The purpose of this study is to identify correlation between the fluid and the acoustic fields. The flow-induced noise was measured using single microphone. The measured noise is related to aerodynamic characteristics of the flow using a single hot wire. The flow-induced noise of the cylinder is characterized in terms of frequency and magnitude. A sharp pick was observed in the far-field pressure at the vortex shedding frequency in which measured with hot wire anemometer. So, one could be concluded that vortex shedding is a source of aerodynamic noise generation. The strouhal number obtained from two devices was almost equal to 0.11 that is in agreement with previous studies. Also, maximum vortex shedding frequency was measured for α=15°. It is observed that sound pressure level is increased with increasing upstream velocity. The overall sound pressure level ranged between 84.2 and 110.95 (dB) for upstream velocities in the range of 5-15 (m/s). The angle of attack has no important effect on overall sound pressure level.
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Article Type: Research Article | Subject: other......
Received: 2017/06/11 | Accepted: 2017/07/27 | Published: 2017/09/8

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